diff --git a/arch/x86/include/asm/io.h b/arch/x86/include/asm/io.h
index 30a3e9776123..6a45ec41ec26 100644
--- a/arch/x86/include/asm/io.h
+++ b/arch/x86/include/asm/io.h
@@ -206,6 +206,7 @@ static inline void __iomem *ioremap(resource_size_t offset, unsigned long size)
 
 extern void iounmap(volatile void __iomem *addr);
 
+extern void set_iounmap_nonlazy(void);
 
 #ifdef __KERNEL__
 
diff --git a/arch/x86/kernel/crash_dump_64.c b/arch/x86/kernel/crash_dump_64.c
index bf43188ca654..994828899e09 100644
--- a/arch/x86/kernel/crash_dump_64.c
+++ b/arch/x86/kernel/crash_dump_64.c
@@ -46,6 +46,7 @@ ssize_t copy_oldmem_page(unsigned long pfn, char *buf,
 	} else
 		memcpy(buf, vaddr + offset, csize);
 
+	set_iounmap_nonlazy();
 	iounmap(vaddr);
 	return csize;
 }
diff --git a/mm/vmalloc.c b/mm/vmalloc.c
index 6b8889da69a6..d8087f0db507 100644
--- a/mm/vmalloc.c
+++ b/mm/vmalloc.c
@@ -516,6 +516,15 @@ static atomic_t vmap_lazy_nr = ATOMIC_INIT(0);
 /* for per-CPU blocks */
 static void purge_fragmented_blocks_allcpus(void);
 
+/*
+ * called before a call to iounmap() if the caller wants vm_area_struct's
+ * immediately freed.
+ */
+void set_iounmap_nonlazy(void)
+{
+	atomic_set(&vmap_lazy_nr, lazy_max_pages()+1);
+}
+
 /*
  * Purges all lazily-freed vmap areas.
  *